Electric switch



Jan. 28, 1941. w. MANNY 2,229;9s-1

ELECTRIC SWITCH Filed Feb. 5, 1938 Inventor Wilhelm Mann,

is Attorhey.

Patented Jan. 2L, 1941 UNITED STATES PATENT OFFICE ELECTRIC SWITCHWilhelm Mann, Dresden, Germany, assignor to General Electric Company, acorporation of New York 8 Claims.

My invention relates to electric switches, more particularly to those ofthe double-throw type such as, for example, snap action switches whereinan energy storing device comprising a spring or its equivalent isoperatively related to a movable switch member for actuating the samebetween limiting circuit controlling positions, and has for itsprincipal object the provision of an improved switch of the aforesaidtype which can be operated in predetermined succession to both contactmaking and intermediate positions. A further object of my invention isto provide a double-throw snap action switch which can be operated fromone contact closing position to another and then to a blockedintermediate circuit opening position. These and other objects of myinvention'will appear in more detail hereinafter.

My invention will be more fully set forth in the following descriptionreferring to the accompanying drawing, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part .of this specification.

Referring to the drawing, Figs. 1 and 2 illustrate an electric switchembodying the present invention in the two limiting positionsrespectively, and Fig. 3 illustrates the switch in an intermediateposition.

In accordance with my invention in a specific structural embodimentthereof, a cam controlled switch wherein a cam controls the release ofspring energy for snap-over operation of a switch actuating element isalso provided with a camcontrol member effective to hold the movableswitch member in an intermediate position against the bias of saidspring in response to a predetermined movement of the cam structure.

Referring more particularly to the drawing,

the cam structure includes a main actuating cam I secured to anoperating shaft at I and operatively related to the energy storingdevice, such as a spring 2, and to the movable switch member 3 pivotallymounted at 4 for rotation between two limiting positions defined by thecontacts 5 and 6. The movable contact I is shown in Fig. 1 in contactengagement at 6 and is held in this position by the spring 2 in a mannerpresently described.

The ram I is provided with suitably designed cam surfaces at 8 and 9 forco-action with a crank III that is pivotally mounted at I I and carriesa cam engaging roller I2 at one part and a pivoted link I3 at anotherpart. The link I3 is provided with a cam portion I4 that is held againsta roller I5 of the movable switch member 3 by the bias of spring 2 whichis connected to the link I3 at I6.

In the arrangement so far described, it will be apparent that rotationof the cam I in accord- 5 ance with the actuation of the operating shaftI' is effective, by reason of the cam surface at I4, to move the switchmember 3 by snap action into engagement with either contact 5 or 6. Theupper limiting or circuit controlling po 10 sition is shown in Fig. 2wherein the cam I has moved clock? se approximately 45 from the positionshown in Fig. l to stress the spring 2 and lower the link I3 for movingthe roller I5 of the movable switch member by snap action past 15 thehigh point of the cam portion I4.

For the purpose of moving the switch member 3 to an intermediateposition and holding the same in a positive manner in such position,there is provided an additional cam structure indicated at H. The cam I1is also mounted on the shaft I so that it has a fixed angular relationwith respect to the cam I. The cam I1 is operatively related to theswitch member 3 through a stop member, such as a crank I8 piv- 25 otedat I9 and provided with a roller 20 coacting with the cam face II. Anextension 2| is adapted to engage the switch lever 3. Accordingly, itwill be noted that the cam II, which is provided with a suitablydesigned operating 30 face I1 is operable to rotate the crank I8counterclockwise as indicated in Fig. 3 to serve as a stop and hold theswitch member in an intermediate or open circuit position against thebias of spring 2.

The cam faces of the cam portions I and H can be suitably designed sothat rotation of the shaft I in a given direction is effective to causea predeterminedsequence of switching operations including definite stoppositions of the 40 switch member at both limiting and intermediatepositions. I

It should be understood that my invention is not limited to specificdetails of construction and arrangement thereof herein illustrated, and45 that changes and modifications may occur to one skilled in the artwithout departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric switch of the double-throw type comprising a movableswitch member operable between two limiting positions, means in whichenergy is adapted to be stored for moving said member by snap action toeither of said positions, 55

means operable independently of said energystoring means for holdingsaid member in an intermediate position, and means comprising anoperating member movable in one direction to energize saidenergy-storing means and to operate said holding means.

2. An electric switch of the double-throw type comprising a movableswitch member operable between two limiting positions, spring means tormoving said member by snap action to either of said positions, cam meansoperable independent- 1y of said spring means for holding said member inan intermediate position, and means comprising an operating membermovable in one direction to energize said spring means and to operatesaid holding means,

3. An electric switch of the double-throw type comprising a/movableswitch member operable between two limiting positions, a springoperatively related to said member, cam means for storing energy in saidspring for efl'ecting movement of said member by snap action to eitherof said positions, additional cam means operable independently of saidspring for holding said member in an intermediate position, and meanscomprising an operating member rotatable in one direction to actuateboth of said cam means.

4. An electric switch of the double-throw type comprising a movableswitch member operable between limiting positions, a spring operativelyrelated to said member for causing snap movement thereof to either ofsaid positions, cam means for stressing said spring for effecting theaforesaid snap action, additional cam means operable to hold said switchmember at an intermediate position against the bias of said spring,-

and a member continuously rotatable in one direction to actuate said twocam means.

5. An electric switch of the double-throw type comprising a movableswitch member operable between two limiting positions, a springoperatively related to said member for causing snap action to either ofsaid positions, a cam for stressing said spring for effecting said snapaction, a second cam having a fixed angular relation with respect tosaid first cam, and a stop member operatively related. to said secondcam and said switch member for holding said switch member against thebias of said spring in an intermediate position whereby predeterminedro= tation of said cams is effective to move said switch member inpredetermined succession with respect I to said limiting andintermediate positions.

6. An electric switch of the double-throw type comprising a movableswitch member operable between two contact closing positions and meansfor actuating said switch member comprising a rotatable member, means inwhich energy is stored by movement of said rotatable member in onedirection for moving said switch member from one contact closingposition to another contact closing position, and means controlled bylfurther movement of said rotatable member in said one direction formoving said switch member from said other contact closing position to aposition intermediate both of said contact closing positions andblocking the switch member in said intermediate position.

7. Anelectric switch of the double-throw type comprising a movableswitch member operable between two contact closing positions, and meansfor actuating said switch member comprising a movable member, meansresponsive to the movement of said movable member in One direction formoving said switch member from one contact closing position to anothercontact closing position, and means controlled by further movement ofsaid movable member in said one direction for moving said switch memberfrom one of said contact closing positions to a position intermediateboth of said contact closing positions and blocking the switch member insaid intermediateposition.

8. An electric switch of the double-throw type comprising a movableswitch member operable between two contact closing positions and meansfor actuating said switch member comprising a movable member, meansresponsive to the movement of said movable member in one direction formoving said switch member from one contact closing position 'to' anothercontact closing position and to the movement of said movable'member inthe opposite direction for moving the switch member back to said onecontact closing position, and means controlled by further movement ofthe movable member in said one direction when the switch member is insaid other contact controlling position for moving said switch memberfrom said other contact closing position to a position intermediate bothof said contact closing positions and blocking the switch member in saidintermediate position.

WILHEIM MANN.

